Device for cutting filamentary material



A. LOB-GE DEVICE FOR CUTTING FIIAMENTARY MATERKAL Filed 22. 1941 ZNVENTOR ALv/N L00 135 ATTORNE Patented Apr. 7, 1942 2,278,662 DEVICE FOR CUTTING FILAMENTARY MATERIAL Alvin Lodge, Meadville, Pa., assignor to Amer- I lean Viscose Corporation, Wilmington, Del., a

corporation of Delaware Application August 22, 1941, Serial No. 407,855

. 9 Claims.

This invention relates to the type of cutter for filamentary material which utilizes centrifugal force for directing the filamentary bundle to be cut to the cutting knives, the prototype being shown in the Beria Patent 1,723,998.

The patented device is incapable of producing a wide range of lengths of fibers unless a different-sized disc is employed. Some variation may be obtained by employing a plurality of knives about the periphery of the rotating disc and an additional but somewhat limited variation may be obtained by varying the speed of rotation of the disc. However, the maximum length of fibers obtainable is limited by the fact that insufficient centrifugal force is exerted by the disc when it is slowed down to an excessive degree in attemptin to obtain a longer time between cuts by the knife. On the other hand, increasing the speed of rotation of the disc is offset by the fact that -the higher rotation produces a higher frequency of cuts. Furthermore, if dry yarn or tow is being handled, it is imperative that the cutting blade make contact with the disc or some other cutting member in order to provide a shearing cut with the least damage to the staple being produced. Because of the very high speed necessary to obtain suflicient centrifugal force to overcome the friction of the dry yarn or tow in order to pull it through the disc at a rate suitable for the production of staple of reasonable length, the wear of the stationary knife in contact with the rapidly rotating disc is excessive and the life of the cutter is therefore relatively short.

' It is an object of the invention to so modify this type of apparatus that a much wider vari' ation in length of fiber may be obtained without the necessity of replacing parts of the cutter, and/or the wider range may be obtained by replacing a single part of the apparatus. A further object is to provide a form of apparatus in which the relative speed between the knife and disc is reduced even at high speeds of the disc so that dry yarn or tow may be as effectively handled as wet yarn or tow without the necessity to recondition or replace the knives at excessive- 1y short intervals as heretofore.

In the drawing, illustrative of the invention, Figure 1 shows a cross-sectional view of the apparatus taken on line II of Figure 2,

Figure 2 is a front elevation of the device with a part cut away,

Figure 3 shows a modified cutting ring, Figure 4 is a cross-sectional view of a detail taken ,on lines I i- 1V of Figure 2'.

Figures 1, 2, and 4 show a form of apparatus constructed in accordance with the invention.v

which concentric hollow shaft 5 is mounted for;

rotation. The cutter ring 3 comprises inner and outer faces 6 and 1 respectively which support the blades 8 which may be of any suitable numher, four being shown in Figure 2. The blades 8 may be fixedly secured between the faces 6 and l of the cutter ring in any suitable fashion, such as by clamping ,with bolts, cap screws, or machine screws. The cutter ring is fastened to a flanged head 9 formed upon the end of th hollow shaft 5. This hollow shaft is in turn supported within the bearing l0 upon any suitable base or support, such as that designated by H in the drawing. A bushing may be provided at l2 between the central shaft 4. and 'the concentric hollow shaft 5. The disc 2 is provided with a guideway l3 withinwhich two members l4 and i5 shaped to fit in the guide are pressed apart by the spring I6 acting within recesses I1 and I8 in the respective members, One of the two members, namely the member I5, is provided with a channel I! having the substantially axially directed entrance 20 and the substantially radially extending portion 2| for guiding the filamentary bundle into the path of the knife blades 8.

In operation of the device, the feeding disc may be given a high speed of rotation, such as 9500 R. P. M. and the'cutting ringmay be given a somewhat higher velocity, such as 10,000

E. P. M. With the four blades in the cuttin ring, there will result 2,000 cuts per minute.

whereas if the centrifugal'disc had been rotated at 9500 R. P. M. against a stationary blade such as in the patent cited, there would have resulted a total of 9500 cuts per minute. The reduction in the cutting frequency in accordance with the invention while-permitting the high speed of rotation results in the production of correspondingly lengthened fibers and in materially lengthening the productive life of-the cutter. The cut fibers fly'outwardly from between the blade 8 and faces 6 and l to any suitable receptacle.

While four blades have been shown in the cutting ring in Figure 2, the invention is not limited to any particular number of blades in the ring. Instead, the ring may three,

k be provided with one, two, or any integral number of blades greater or less than the four shown. When only I or 2 blades are employed, the inner and outer faces of the cutting ring may be held together by pins suitably spaced at the outer edges or the respective faces of the rings. It is not essential for all purposes that the cutting ring rotate faster than the centrifugal feeding disc. If desired, the cutting ring may be rotated at a lower speed than the Xeedlng disc, provided in such event that the blades or the cutting means be disposed with their cutting edges trailing instead of leading as shown in Figure 2.

The cutting ring of the invention may be replaced by others having a different number of cutting blades, or alternatively certain of the blades, or all of them, may be replaceable or removable in any given cutting ring. For example, the cutting ring of Figure 3 (shown on a smaller scale than that in Figure 2) is provided with twenty blades. This, like the one in Figure 2, may be driven at any desirable speed depending upon the length of fiber desired. If the cutting ring having twenty blades is held stationary (or very slowly rotated one way or the other) while the feeding-disc is rotated at 10,000 R. P. M., 200,000 cuts per minute (or more or less) will be made and the product is suitable for use as fiocl-r." However, by rotating the twenty-bladed cutting ring at 9600 R. P. M. while rotating the disc at 9500 R. P. M., the product will correspond with that made with the four-bladed cutting ring operated at 10,000 R. P. M. and the disc operated at 9500 R. P. M.

While a preferred embodiment of the invention has been disclosed, the description is intended to be illustrative only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the invention as defined by the appended claims.

What I claim is:

1. An apparatus of the character described comprising cutting means, means for driving said cutting means in an arcuate path, and centrifugal means having its axis of rotation extending within said path for feeding a filamentary bundle outwardly therefrom into the path of said cutting means.

2. An apparatus of the character described comprising a rotatable annular cutting means, and centrifugal means having its axis voi rotation within said path for feeding a filamentary bundle outwardly therefrom into the path of said cutting means.

3. An apparatus of the character described comprising cutting means, means for driving said cutting means in an annular path, and centrifugal means having its axis of rotation extending within said path for feeding a filamentary bundle outwardly therefrom into the path of said cutting means.

4. An apparatus of the character described comprising cutting means, means for driving said cutting means in an annular path, a rotatable member positioned within said path and having a channel therethrough, said channel having a radially extending portion lying in the plane of said path and opening directly into said path, and means for rotating said member about its axis.

5. An apparatus of the character described comprising an annular cutting means rotatable about its axis, and a concentric member rotatable within said annular cutting means, said member having a channel therethrough having a radially extending portion having an opening adjacent the inner periphery of said cutting means.

6. An apparatus of the character described comprising an annular cutting means rotatable about its axis, and a concentric disc rotatable within said annular cutting means, said disc having a generally radially extending guideway, a member slidable in said way and having a channel therethrough having a radially extending portion, and means for resiliently pressing said slidable member against the inner periphery of said cutting means.

7. An apparatus of the character described comprising an annular cutting means rotatable about its axis, a concentric disc rotatable within said annular cutting means, said disc having a central guideway transverse thereof, two members slidable in said way, one of said members having a channel therethrough having a radially extending portion, a spring between said members whereby said members are pressed against the inner periphery of said cutting means insubstantially symmetrically arranged positions.

8. An apparatus of tne character described comprising a rotatable annular cutting means, and centrifugal means for feeding a filamentary bundle outwardly therefrom into the path of said cutting means, said centrifugal means and the annular cutting means being arranged concentrically.

9. An apparatus of the character described comprising cutting means, means for driving said cutting means in an annular path, and centrifugal means for feeding a filamentary bundle outwardly therefrom into the path of said cutting means, said centrifugal means and the cutting means being arranged concentrically.

ALVIN 

